Abstract <p>Spontaneous combustion of coal is one of the important factors affecting coal mine safety. Many coal mine accidents are caused by spontaneous combustion of coal In order to study the influence of particle size on coal oxidation temperature rise, a temperature programmed test system was used to study the gas generation law in oxidation temperature rise of coal samples with different particle sizes in Dongrong Coal Mine. The thermal reaction of five different particle sizes of coal was studied by differential scanning calorimetry in thermal method The results show that the smaller the particle size, the greater the gas release of coal samples; With the decrease of particle size of coal sample, the reaction area between coal sample and oxygen increases, and the cross point temperature corresponds The particle size of coal sample has obvious influence on the tendency of coal spontaneous combustion. It is of practical significance to study the difficulty of coal spontaneous combustion by using activation energy. According to the experimental data, it is necessary to prevent and control coal mine fires.</p>